I have an issue where the pcv valve won't 'lock' into the valve cover on an 02 Sport 4.0 SOHC. I've felt in the valve cover, and it does not appear that there are 'nibs' for the pcv valve to twist lock into. Is there a grommet that has come out? It does not seem likely, since there's barely enough room for the pcv valve to fit in the valve cover hole. Assuming the nibs broke off, any suggestions on how to repair this? I can't seem to get a grommet to fit in the opening and fit to the pcv valve. Would rtv work? I'm assuming not, since the valve cover is plastic (and, I can't figure out how to apply force to the pcv valve to keep it tight to the valve cover). Should I disconnect it and replace it with some sort of breather? I'm experiencing rough idle and poor mileage as a result of this....Any thoughts would be appreciated.